Abstract

Introduction

Myasthenia gravis is a neuromuscular junction post-synaptic autoimmune disorder. Myasthenic
crisis is characterized by respiratory failure requiring mechanical ventilation. Takotsubo
cardiomyopathy is a rare clinical syndrome defined as a profound but reversible left
ventricular dysfunction in the absence of coronary artery disease.

Case presentation

We report a unique case of a 60-year-old Hispanic woman with myasthenia gravis who
developed takotsubo cardiomyopathy and concomitant myasthenic crisis that appear to
have been triggered by a stressful life event. On admission, she presented with severe
mid-sternal chest pain and shortness of breath shortly after a personally significant
stressful life event. A pertinent neurological examination showed bilateral facial
weakness and right ptosis. The left ventriculogram showed apical ballooning with hyperdynamic
proximal segments with sparing of the apex. Her troponin I level was elevated, while
cardiac catheterization revealed no significant coronary artery disease. The findings
were consistent with takotsubo cardiomyopathy. Shortly after cardiac catheterization,
she developed bilateral ophthalmoparesis and significant bulbar and respiratory muscle
weakness. Forced vital capacity values were persistently less than 1 L. The patient
developed respiratory failure and required endotracheal intubation. After plasmapheresis
and corticosteroid treatment, her clinical course improved with successful extubation.
A normal left ventricle chamber size and a normal ejection fraction were noted by
an echocardiogram repeated 10 months later.

Conclusion

This is the first reported case of the simultaneous triggering of both takotsubo cardiomyopathy
and myasthenic crisis by the physiologic consequences of a state of severe emotional
stress. We hypothesize that the mechanism underlying the rare association of takotsubo
cardiomyopathy with myasthenic crisis involves excessive endogenous glucocorticoid
release, a high-catecholamine state, or a combination of both. We advocate careful
cardiac monitoring of myasthenia gravis patients during acute emotional or physical
stress, as there is potential risk of developing takotsubo cardiomyopathy.